Flexduct 465C R8 Flex Air Duct 4 Inches Fiberglass Black

Product Description

The FLEXDUCT 465C is a UV-inhibited fiberglass flexible air duct with an R8 insulation rating, designed for residential and light commercial HVAC distribution systems. The 4-inch diameter construction uses a fiberglass core to deliver thermal efficiency and noise attenuation across supply and return air runs. At R8, this duct provides high insulation performance suited for installations in unconditioned spaces such as attics, crawlspaces, and mechanical rooms. The black outer jacket provides UV resistance for installations with incidental light exposure. Licensed HVAC technicians and sheet metal contractors are the typical installers for this product.

This flex duct is used in forced-air heating and cooling systems where flexible connections are needed between rigid ductwork and supply registers or air handlers. The 4-inch diameter fits standard trunk-to-branch takeoffs and ceiling diffusers common in residential construction. The 25-foot bag length provides a full run for most room branch circuits without splicing. R8 insulation meets or exceeds energy code requirements in many climate zones, making it a standard choice for above-ceiling and below-floor duct runs in new construction and retrofit projects.

Key Features

• R8 insulation rating for high thermal resistance in unconditioned spaces
• 4-inch diameter fits standard residential branch duct takeoffs and diffusers
• UV-inhibited outer jacket resists degradation from incidental light exposure
• Fiberglass construction provides both thermal insulation and acoustic dampening
• 25-foot length per bag allows full branch runs with minimal splicing
• Black outer jacket for attic and exposed-installation applications

Compatibility

Designed as an OEM-style replacement and new-installation flex duct for residential and light commercial forced-air HVAC systems using 4-inch branch duct connections.

Installation Notes

Installation should be performed by a licensed HVAC technician or sheet metal contractor in accordance with SMACNA guidelines and applicable local mechanical codes. Power down or lock out the air handling unit before connecting or disconnecting duct sections. Avoid compressing or sharp-bending the duct, as both conditions reduce airflow and effective R-value. Secure all connections with approved metal bands or draw bands and seal with UL 181B-listed mastic or tape.

Technical Specifications

• Insulation Rating: R8
• Diameter: 4 inches
• Length: 25 feet
• Material: Fiberglass
• Color: Black
• UV Resistance: UV-Inhibited Outer Jacket
• Category: Flex Duct

Standard Information

• Brand: FLEXDUCT
• Manufacturer Part Number: 465C